He’s a young player of 24 who hits for mad power. As a bonus DeJong significantly upgraded the defense at shortstop after displacing Aledmys Diaz. This combination of longballs and leather earned DeJong enough votes to finish 2nd in the NL voting for 2017 Rookie of the Year.

What a year. DeJong began his first season at Triple A Memphis in April, was promoted to the Cardinals in late May, got returned to Memphis for a spell, was called back up to the big club, became the starting shortstop in late June, and took over as the No. 3 hitter in Mike Matheny’s lineup in late July. By the end of the season DeJong had 25 homers, a .532 slugging percentage and had generated the most power by a Cardinals rookie since Albert Pujols in 2001. The Cardinals rewarded DeJong by paying him bigger money ahead of schedule in the form of a six-year contract for $26 million.

There was only one red flag.

Flawed plate discipline.

DeJong had a 28 percent strikeout rate and a 4.7% walk rate in 2017. Such a lopsided ratio is a threat to any hitter’s longterm viability and success, but Cardinals president John Mozeliak believes DeJong had the self-awareness and intelligence to adjust.

The goal, Mozeliak told me, was for DeJong to get the strikeout rate down to near 20 percent and to increase his the walk rate a lot closer to 10 percent. As 2017 went along, DeJong lowered his K rate each month and began walking a little more frequently later in the season.

A couple of weeks into the season, the K-BB ratio still requires major corrections. DeJong had a two-day splurge in the third and fourth and games of the season, rocking the Mets and Brewers for three homers and five RBIs.

But in the last eight games through Wednesday, DeJong was 6 for 29 with 13 strikeouts and no walks. DeJong was given the day off — at least as a starter — when the Cardinals and Brewers concluded their three-game series Wednesday afternoon at Busch Stadium. DeJong entered in the 8th inning to pinch hit against Milwaukee’s nasty lefty Josh Hader … and struck out. The Cardinals list the game, 3-2. And they dropped yet another home series to the Brewers.

Even though DeJong is batting .295 with a .326 onbase percentage and .523 slugging percentage over his first 12 games, it’s a mistake to overlook his early trend in swings and misses … and there have been many misses.

DeJong struck out 19 times with only one walk in his first 46 plate appearances. Early season or not, a 41.3 percent strikeout late is alarming, and it’s nearly double the league percentage of 21%.

Moreover, DeJong’s swing-and-miss rate of 43.8 percent puts him right at the bottom with the Cubs’ Ian Happ for the worst whiff rate in the majors among 198 qualifying MLB hitters. DeJong has put the ball in play on only 31.3 percent of his swings, which ranks 168th on that list of 198 hitters.

According to the available data at STATS LLC, which goes back to 1988, the highest swing-miss rate by a Cardinal in a season (minimum 350 PA) was 36.7 percent by Mark McGwire in his final big-league season (2001.) Randal Grichuk, who struggled terribly with his strike-zone judgment, never had a higher swing-miss rate than 31.6 percent during a season with the Cardinals.

Having lost patience with Grichuk, the Cardinals traded him to the Blue Jays in the deal that put reliever Dominic Leone in the St. Louis bullpen. By the way: Grichuk is off to a horrendous start for Toronto, with 3 hits and 12 strikeouts in 35 at-bats.

DeJong has plenty of time to adapt. And he isn’t the only Cardinal with higher than normal swing-miss issues. Matt Carpenter, for example, has a swing-miss rate of 35.3 percent. Carpenter has never had a swing-miss rate higher than 21.5 percent in a season. The Cardinals’ overall contact rate by non-pitchers — 76.2 percent is 14th in the majors and 7th in the NL. And their team strikeout rate of 25 percent is the third worst in the league.

Here are some of the specifics on DeJong in the early going; all but the first stat comes to us courtesy of our friends at Inside Edge. (Thank you.) …

— DeJong is taking more pitches than he did last season … and as a result, he’s absorbing an increase in called strikes. His “take” rate was 48.4 percent last season. That’s up to 59 percent in the first two weeks of ’18. Last year DeJong’s called-strike percentage of 14 percent. Early this season, that number is 21.7 percent.

— DeJong has gotten pull happy, a habit that ultimately led to an offensive collapse by Diaz. DeJong has pulled 64 percent of the balls he’s pit in play, and the 9th highest pct. in MLB.

— DeJong’s swing and miss rate on fastballs (39.5%) is the worst in the majors and way above the league average of 18.4 percent.

— Elevated fastballs gave DeJong problems last season, and that’s true again early this year. He’s swung and missed on 51 percent of the elevated fastballs; that’s the fourth-worst in the majors and considerably poorer than the league average of 24.9 percent.

— Pitchers are also attacking DeJong with low-and-away fastballs. He’s only put 9 percent of those pitches in play … and on low fastballs (any location) his swing-miss rate (37.5%) is 4th worst in the majors and more than double the league 15.7 percent rate,

— DeJong has swung and missed on 57.6% on non-fastballs offered to him this season; that’s 3rd worst in MLB and well off the league average 33.7 percent.

— DeJong has swung and missed on 57.1% of the breaking pitches; that’s the 2nd worst in MLB. League average: 33.7 percent.

— DeJong’s has a swing-whiff rate of 39.5 percent on fastballs — the worst in the bigs; league average is 18.4 percent.

As we can see, DeJong has a lot to fix. But he’s a bright guy. Many hitters are out of sorts. There have been too many cold-weather games, and more days off than normal. It’s not the most favorable environment. And we also knew that DeJong — despite his swell rookie season — was relatively inexperienced and still developing. I think we’ll see improvement. But DeJong can’t put too much pressure on himself; he must stay connected to his confidence. When it comes to believing in himself, he can’t afford to swing and whiff. He can adjust. He must adjust.